Toyota Tacoma (2015-2018) Service Manual: Pump Motor Relay (C1253)
DESCRIPTION
The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU (master cylinder solenoid).
|
DTC No. |
DTC Detecting Condition |
Trouble Areas |
|---|---|---|
|
C1253 |
Open in motor system circuit (motor input circuit) |
|
WIRING DIAGRAM
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CAUTION / NOTICE / HINT
NOTICE:
- When replacing the skid control ECU (master cylinder solenoid), perform
zero point calibration (See page
.gif)
). - Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT:
Start the inspection from step 1 when using Techstream and start from step 3 when not using Techstream.
PROCEDURE
|
1. |
PERFORM ACTIVE TEST USING TECHSTREAM (MOTOR RELAY) |
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn Techstream ON.
(d) Select the Active Test mode on the Techstream.
ABS/VSC/TRAC|
Tester Display |
Test Part |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
Motor Relay |
Turns motor relay |
ON / OFF |
Operation of motor can be heard |
(e) Check for operation sound of the motor when it is operated with Techstream.
OK:
The operation sound of the motor can be heard.
| NG | .gif) |
GO TO STEP 3 |
|
.gif)
|
2. |
RECONFIRM DTC |
(a) Clear the DTCs (See page
).
(b) Turn the ignition switch to OFF.
(c) Depress the brake pedal more than 20 times.
(d) Turn the ignition switch to the ON position.
(e) Wait until the pump motor stops.
(f) Depress the brake pedal several times until the pump motor is turned on.
(g) Wait until the pump stops.
(h) Repeat (f) and (g) three times.
(i) Check if the same DTCs are recorded.
|
Result |
Proceed to |
|---|---|
|
DTC output |
A |
|
DTC not output |
B |
| A | |
REPLACE HYDRAULIC BRAKE BOOSTER |
| B | |
END |
|
3. |
CHECK HARNESS AND CONNECTOR (+BM, +BM2 TERMINAL) |
|
(a) Disconnect the skid control ECU (master cylinder solenoid) connectors. |
|
(b) Measure the voltage.
Standard Voltage:
|
Tester Connection |
Specified Condition |
|---|---|
|
S1-2 (+BM1) - Body ground |
10 to 14 V |
|
S2-2 (+BM2) - Body ground |
10 to 14 V |
(c) Reconnect the skid control ECU (master cylinder solenoid) connectors.
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR (+BM1 AND +BM2 CIRCUIT) |
|
|
4. |
CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BODY GROUND) |
|
(a) Disconnect the skid control ECU (master cylinder solenoid) connectors. |
|
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(b) Measure the resistance.
Standard Resistance:
|
Tester Connection |
Specified Condition |
|---|---|
|
S1-1 (GND1) - Body ground |
Below 1 Ω |
|
S1-32 (GND2) - Body ground |
Below 1 Ω |
|
S2-4 (GND3) - Body ground |
Below 1 Ω |
(c) Reconnect the skid control ECU (master cylinder solenoid) connectors.
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT) |
|
|
5. |
RECONFIRM DTC |
(a) Clear the DTCs (See page
).
(b) Turn the ignition switch to OFF.
(c) Depress the brake pedal more than 20 times.
(d) Turn the ignition switch to the ON position.
(e) Wait until the pump motor stops.
(f) Depress the brake pedal several times until the pump motor is turned on.
(g) Wait until the pump stops.
(h) Repeat (f) and (g) three times.
(i) Check if the same DTCs are recorded.
|
Result |
Proceed to |
|---|---|
|
DTC output |
A |
|
DTC not output |
B |
| A | |
REPLACE HYDRAULIC BRAKE BOOSTER |
| B | |
END |
Brake Booster Pump Motor on Time Abnormally Long (C1252)
DESCRIPTION
The motor relay (semiconductor relay) is built into the master cylinder solenoid
and drives the pump motor based on a signal from the skid control ECU (master cylinder
solenoid).
...
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DESCRIPTION
The accumulator pressure sensor is connected to the skid control ECU in the master
cylinder solenoid.
DTC No.
DTC Detecting Condition
Trouble Areas
...
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DIAGNOSIS SYSTEM
1. DESCRIPTION
The ECU stores trouble codes when malfunctions occur.
The diagnostic system allows for reading of the trouble codes from the DLC3.
Use the Techstream to help diagnose and repair the problem.
2. CHECK DLC3
(a) Check the DLC3 (See page ).
3. INSPECT BATTERY VOLT ...
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DESCRIPTION
If the communication line (EFIO-IMI) to the transponder key ECU assembly is stuck
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DTC No.
DTC Detection Condition
Trouble Area
DTC Output Confirmation Operation
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...
